Structural Factors in Effective Charge Model of Solvent Effect Conformations of Acetylcholine

Abstract

In the effective charge model of solvent effect, two structural factors were considered for each atom in a solute molecule; the solvent-shell volume and the surface area which is in contact with solvent. The CNDO/2 calculation of the conformation of acetylcholine in water indicated that the conformational energy map calculated without the structural factors was very similar to that in vacuum, while the stable conformations calculated with the solventshell volume factor were consistent with the conformation experimentally observed in water and those calculated by other theoretical models. The solvent-shell volume factor reflects the steric effect of nonbonded atoms appropriately and plays an important role in the conformational study of molecules in solution.